Microfilm cameras having a servo drive lens supported by a flexible four-bar linkage, have been known.
It is desirable that such a system be capable of producing high resolution images from documents moving at a high rate of speed. Furthermore, the servo mechanism should be capable of responding to the demands of documents of different length and to inter-document gaps of different length. Furthermore, microfilm cameras of this type are generally made as part of a larger machine including separate mechanisms which can provide potential sources of resonance stimulation. For maximum precision, the servo control should employ a feedback transducer that is connected as integrally as possible with the lens, itself. Extraneous motion of the lens thus can be a source of servo instability.